1. Field of the Invention
This invention generally relates to a motorized bicycle derailleur. More specifically, the present invention relates to a motorized bicycle derailleur that includes an arrangement to protect the motor in the event the chain guide is stuck in one of the shift positions.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle.
Recently, bicycles have been equipped with electrical components to make riding easier and more enjoyable for the rider. Some bicycles are equipped with automatic shifting units that are automatically adjusted according to the riding conditions by a cycle computer or control unit. In particular, the front and rear derailleurs have recently been automated.
Generally speaking, the front derailleur is typically secured to the seat tube of the bicycle frame or the bottom bracket. Basically, a front derailleur includes a fixed or base member non-movably secured to a bicycle frame, and a movable member supported to be movable relative to the fixed member. Typically, the fixed member is a tubular clamping member that is secured to the seat tube. The movable member typically has a chain guide with a pair of cage plates for contacting and moving a chain between the front sprockets. The movable member is usually biased in a given direction relative to the fixed member by a spring. The movable member is usually moved relative to the fixed member by pulling and/or releasing a shift control cable that is coupled to the front derailleur. The movable member and the fixed member usually are interconnected through pivotal links. In a manually operated front derailleur, a control cable is connected to one of the pivotal links to apply a torque thereto, thereby causing the links to move the movable section. The control cable is fixed to the link in such a position that an operating force applied to the control cable. This force on the cable is converted into a link swinging torque. In a motorized front derailleur, a motor is used to pull and release a control cable or the motor is connected by a drive train to the front derailleur.
It will be apparent to those skilled in the art from this disclosure that there exists a need for an improved motorized bicycle front derailleur assembly. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.